Sunday, April 26, 2009

A New Favorite Bird

I don't have a single favorite bird. In many cases, my favorite is simply the one I am looking at. On Saturday, I added a new bird to my very long "favorite list" simply because I saw it, photographed it and it's name contains another favorite past-time of mine...

Like many birders in southeast Michigan, I have been known to leave the state during spring migration. That is not to say that Michigan doesn't have any places worth visiting - it certainly does. But one of the premiere places in the Midwest is only an hour from my home, so taking the short trek there now and then is certainly a worthwhile adventure. So, Saturday morning, I hit the road and was at Magee Marsh Wildlife Area by 7:45 am.

In the span of 6 hours or so, I recorded over 80 species. Among the goodies - Worm-eating Warbler, Yellow-breasted Chat, and Summer Tanager (thanks Chuck!). Those were among the best birds of the day simply because I had not recorded them in Ohio before. Adding a state bird now and then can be a tough deal, but 3 in a few hours? Not bad! (My Ohio list is now 219, by the way.) 17 total warbler species were observed. Admittedly, I wasn't birding hard. I took some time for photography, too. A few even sat nicely for me, like the Black-throated Green Warbler seen on the left.

But what was the most interesting bird of the day? The one I can't count, because it is not a species - it is parts of two.

First, a quick note on how a birding list may work. You see a species and you record it on your list. Ta-dah! An American Robin, a Red-tailed Hawk, and a Herring Gull would be three checks on the list right? Each is it's own species and therefore has it's own place on the checklist.

Sometimes, however, a bird is not pure. It is a hybrid. The parents are not the same species, but they are similar enough where they can breed, so in some situations, they do. The case in point is the bird on the left. Called a Brewster's Warbler, it is the offspring of a Blue-winged Warbler and a Golden-winged Warbler. If you look at the photo of "my" bird and compare it with the images of the parent birds, you can clearly see where it has marks that combine traits from the two parents. The gold head and wing-bars are from the Golden-winged, while the predominantly white underbody and black stripe from bill to eye are from the Blue-winged. While this photo does not show it, there is a dash of yellow on the breast which tell us that is an "F1" (first) generation. That can be rather important for field identification because the hybrid young can then go back and mate with "pure" adults in subsequent years, bringing on a whole mish-mash of trait combinations.

Ultimately, as Blue-winged Warblers move north into Golden-winged Warbler territories, the interbreeding results in the long-term loss of the Golden-wings. Their genes are lost as the more dominant genes of the Blue-wings take over. Interestingly enough, if you think about, it is not because they aren't breeding, it is because they are breeding. For the Golden-winged Warbler, the simple act of passing on one's genetic information is, in a sense, dooming some populations.

By the way, lets look at that name again: Brewster's Warbler. Brrrreeeeewwwwster's Warbler. Get it?